The video was shown for the first time on Tuesday on cable channels MTV and VH1.

Attack

It also features a scene in which the singer, dressed in a leopard-print thong, apparently tries to seduce Cherie Blair.

But US callers to the CNN show appeared to perceive the video as an attack on the US, and there were reportedly boos from the studio audience.

Michael maintained he would never "disrespect" Americans' feelings after the 11 September attacks.

Michael: US "has suffered" recently

"There was no plan to release [the song] in your country and I think it would have been disrespectful to make this an issue in a country which obviously has suffered much loss and very recently," he told CNN.

"This was absolutely an attack on Tony Blair, principally, and the perspective which is really predominant in Europe right now that he's not questioning enough of Mr Bush's policies."

"I think in the current climate, it can be very difficult to speak your mind, but sometimes, I believe, we're all in danger and I think this discussion needs to be widened," he said.

'Coward'

Earlier in the week, Michael said in a statement: "I am definitely not anti-American - my feelings about George W Bush, however, are a little different.

"And I know I'm not alone in fearing his politics, and in hoping that our man Tony can be a calming and rational influence on him," said the statement.

Pop Idol judge and BMG records boss Simon Cowell said that Michael was a "coward" for not releasing the song in the US.

"It shows a lack of conviction to write a song about America and not actually release it there," Cowell told the Sun newspaper.

Record deal

But on Friday Michael's spokeswoman told BBC News Online that there had never been any intention to release the record in the US.

"It never was going to be released there - [his previous single] Freeek wasn't released in the US either.

"He doesn't have a record deal in the US," she said.

The single, which goes on sale in the UK on 5 August, is set for release in Europe, Asia, Australia and South America.